1. Field of the Invention
The present invention generally relates to antennas, and more particularly to patch antennas.
2. Brief Discussion of Related Art
Patch antennas can transmit and/or receive electromagnetic waves. Free-space electromagnetic waves propagating through a medium, such as air, are received by patch antennas, which can transform these electromagnetic waves into guided electromagnetic waves by inducing such waves on feedlines of the patch antennas. The induced guided electromagnetic waves can be fed into an integrated circuit that can decipher the information from the received waves. To transmit information, patch antennas can generate guided electromagnetic waves on the feedline, which can induce an electric field surrounding the antenna to form a free-space propagating electromagnetic wave that radiates from the patch antenna.
Performance of a patch antenna is typically dependent on a distance of a patch element of the patch antenna from a ground plane of the patch antenna. For example, in conventional patch antennas, patch elements that are spaced at a closer distance to the ground plane generally have a higher quality factor (Q) than patch elements spaced at greater distance from the ground plane. As a result, the bandwidth of a conventional patch antenna decreases as patch elements move closer to the ground plane and increases as the patch elements move farther away from the ground plane.
Conventional feedline configurations can have the effect of limiting the bandwidth by introducing reactance and, in certain cases, by introducing its own radiation effects. As a result, the performance of conventional patch antennas is generally limited by these conventional feedline configurations. Thus, there is a desire for patch antennas that reduce and/or eliminate deleterious effects of feedline configurations to improve the performance of patch antennas.